Yucca plant named ‘Silver Anniversary’

ABSTRACT

A new cultivar of  Yucca  plant named ‘Silver Anniversary’ that is characterized by compact habit, moderate plant vigor, production of multiple offsets, powder-blue colored foliage which is hardy in USDA Zone 5b, and a tall inflorescence consisting of burgundy stems and cream-white flowers, is disclosed.

Genus and species: Yucca filamentosa x Yucca pallida.

Variety denomination: ‘Silver Anniversary’.

BACKGROUND OF THE NEW PLANT

The present invention relates to a new and distinct variety of Yucca,commonly known as soapwort, which is grown for use as an ornamentalplant for planted containers or for planting in the landscape. ‘SilverAnniversary’ is known botanically as Yucca filamentosa x Yucca pallidaand will be referred to hereinafter by the cultivar name ‘SilverAnniversary’.

‘Silver Anniversary’ arose from a Yucca breeding program commenced bythe inventor in a nursery in Raleigh, N.C. in 2013. The goals of thebreeding program were to develop novel varieties which grow and multiplyrapidly while maintaining a compact habit, and developing varieties withstriking foliage color and cold-hardiness in zone 7b. ‘SilverAnniversary’ was selected from a population of diverse seedlings whichwere raised from seed arising from the open-pollination of two speciesof Yucca: the female parent, an unknown Yucca filamentosa, commonlyknown as Adam's needle, and the male parent, an unknown Yucca pallida,commonly known as pale Yucca. A single seedling, designated ‘SilverAnniversary’, exhibited a combination of greatly increased vigor,presumably arising from the more vigorous species Yucca filamentosa,with the attractive powder-blue colored foliage of Yucca pallida.

‘Silver Anniversary’ was first propagated in 2016 at a nursery inRaleigh, N.C., using the method of division of underground stems. Theinventor has observed that all asexually reproduced plants of ‘SilverAnniversary’ have remained stable and have reproduced true to type insuccessive generations of asexual reproduction via division ofunderground stems.

SUMMARY

The following traits have been repeatedly observed and represent thedistinguishing characteristics of the new Yucca variety named ‘SilverAnniversary’. In combination, these traits set ‘Silver Anniversary’apart from all other varieties of Yucca known to the inventor. ‘SilverAnniversary’ has not been tested under all possible conditions andphenotypic differences may be observed with variations in environmental,climatic and cultural conditions, however, without any variance ingenotype:

-   -   1. In its first year of growth, ‘Silver Anniversary’ establishes        a single stemless tight rosette of foliage.    -   2. In successive years of growth, ‘Silver Anniversary’ produces        multiple offsets of rosetted foliage.    -   3. The emerging and juvenile foliage of ‘Silver Anniversary’        exhibits gentle recurving which straightens as the plant and        foliage matures.    -   4. The leaves of ‘Silver Anniversary’ are powder-blue in color.    -   5. After four months in the ground (after planting a well-rooted        division), ‘Silver Anniversary’ is 30 cm in height and width.    -   6. After twelve months in the ground, ‘Silver Anniversary’        achieves 120 cm in height and 70 cm in width (excluding the        height of the inflorescence).    -   7. ‘Silver Anniversary’ produces its first inflorescences after        one year of growth.    -   8. The inflorescence of a mature plant of ‘Silver Anniversary’        will extend 75 cm to 1 m above the foliage canopy.    -   9. The stems of the inflorescence of ‘Silver Anniversary’ are        burgundy in color.    -   10. The flowers of the inflorescence of ‘Silver Anniversary’ are        bell-shaped and cream-white in color.    -   11. ‘Silver Anniversary’ is hardy in USDA Zones 5b to 10b.

DESCRIPTION OF THE PHOTOGRAPHS

The accompanying color photographs illustrate the overall appearance ofthe new Yucca variety named ‘Silver Anniversary’ showing color as trueas it is reasonably possible to obtain in color reproductions of thistype. Both drawings were made from photographs of an establishedin-ground plant growing at a nursery in Raleigh, N.C.

FIG. 1 depicts a one-year-old plant of ‘Silver Anniversary’. No flowershave been produced in the first growing season.

FIG. 2 depicts a close-up view of the inflorescence of ‘SilverAnniversary’ which was observed on a three-year-old in-ground plant.

Photographs were made using conventional techniques and although flowerand foliage color may appear different from actual color due to lightreflectance, they are as accurate as possible by conventionalphotography.

DESCRIPTION OF THE NEW VARIETY

The following is a detailed botanical description of the new Yuccacultivar named ‘Silver Anniversary’. Data was compiled from plants grownoutdoors in Raleigh, N.C. The observed plants were 3-years-old. Allcolor determinations are in accordance with the 2007 edition of TheRoyal Horticultural Society Colour Chart except where general colorterms of ordinary dictionary significance are used.

-   Botanical and plant description:    -   -   Family.—Asparagaceae.        -   Genus.—Yucca.        -   Species.—filamentosa x pallida.        -   Common name.—Soapwort.        -   Use.—Ornamental plant for use in planted containers or in            the landscape.        -   Parentage.—‘Silver Anniversary’ arose as a selected seedling            from a population of plants raised from seed resulting from            the open-pollination of plants of the two species Yucca            filamentosa and Yucca pallida.        -   Habit.—Compact, dome-shaped foliage canopy.        -   Vigor.—Moderate overall plant growth (plant size); vigorous            production of offsets.        -   Plant dimensions (in-ground, excluding inflorescence).—After            four months, 30 cm in height and width. After twelve months,            120 cm in height, 70 cm in width. After three years, 1.5 m            in height, 1 m in width.        -   Plant hardiness.—5b to 10b.        -   Propagation.—Division of underground stem or root cuttings.            Division of basal shoots in tissue culture.        -   Root system.—Fine and fibrous.        -   Time to develop roots.—2 months to full rooting in a quart            container.        -   Crop time.—2 months after planting a rooted division in a            quart container; 6 months after planting a quart container            into a 1-gallon container.        -   Disease susceptibility and resistance.—Susceptible to Yucca            Plant Bug, Halticotoma valida.        -   Special growing considerations.—‘Silver Anniversary’ is            adaptable but prefers well-drained soil and a full-sun to            part-sun aspect.        -   Drought/heat tolerance.—This variety withstands the hot and            humid conditions of Raleigh, N.C. (zone 7b), and is tolerant            of drought once established.        -   Stem.—None visible above ground; ‘Silver Anniversary’ is            acaulescent.-   Foliage:    -   -   Quantity of leaves.—Very numerous; exceeds 250 on a            3-year-old plant.        -   Leaf shape.—Oblanceolate.        -   Leaf division.—Simple.        -   Leaf arrangement.—Spirally arranged.        -   Leaf apex.—Acuminate with apical spine.        -   Shape of apical spine.—Keel-shaped.        -   Color of apical spine.—RHS 167A.        -   Length of apical spine.—4.0 mm to 14.0 mm.        -   Leaf base.—Truncate.        -   Venation pattern.—Parallel; veins barely visible on either            surface.        -   Leaf margins.—Entire; outermost edges appear white or            translucent.        -   Leaf attachment.—Sheathing.        -   Leaf surfaces (both upper and lower).—Scabrous.        -   Leaf pubescence.—None.        -   Leaf width (widest point, approximately halfway between base            and apex).—39.0 mm.        -   Leaf length.—Up to 69.0 cm.        -   Leaf color (both surfaces).—Close color match not found:            between RHS 188D and RHS 122D.-   Inflorescence:    -   -   Bloom period.—May to June.        -   Inflorescence diameter.—30.0 cm.        -   Form.—Panicle.        -   Flowers per panicle.—350 to 450.        -   Inflorescence height, from ground level.—1.7 m to 2.0 m;            60.0 cm to 70.0 cm for inflorescence only.        -   Flower diameter.—1.2 cm to 1.6 cm.        -   Stem.—Scape, borne above foliage and extending to 111 cm to            134 cm height above foliage.        -   Stem length.—18 cm to 22 cm.        -   Stem diameter.—3 cm to 4 cm.        -   Stem color.—Emerges light green, becomes (or ages to) RHS            143C and RHS 144A.-   Flowers:    -   -   Arrangement.—Alternate and composed of 6 tepals.        -   Type.—Campanulate.        -   Tepal height or length.—4.5 cm to 5.5 cm.        -   Tepal width.—1.6 cm to 2 cm.        -   Tepal shape.—Ovate.        -   Tepal apex.—Acuminate.        -   Tepal color.—Creamy white (RHS 155A).        -   Tepal texture.—Leathery.        -   Petal dimensions, color, texture if different.—No            difference, all tepals.        -   Fragrance.—Present, musty.        -   Lastingness of individual flower.—1 to 4 days.        -   Lastingness of inflorescence.—20 to 30 days, with stalk            persisting until next season.        -   Pedicel.—Absent; flowers are sessile.-   Reproductive organs:    -   -   Stamens.—6 in number; 1.6 mm to 1.8 mm in length; color:            white.        -   Anthers.—Small, globular; color: brown/yellow.        -   Pistils.—3.        -   Stigma.—White.        -   Pollen quantity.—Slight; color: Creamy white.        -   Fruit or capsules.—Dry dehiscent capsule.        -   Seed.—Papery, black.

COMPARISON TO PARENTAL LINES

‘Silver Anniversary’ may be compared with its parents as follows.Whereas the female parent Yucca filamentosa has green foliage, thefoliage of ‘Silver Anniversary’ is powder blue in color. Whereas themale parent Yucca pallida and ‘Silver Anniversary’ both bear powder bluefoliage, plants of ‘Silver Anniversary’ exhibit greatly increased vigor.

The variety which the inventor considers to most closely resemble‘Silver Anniversary’ is ‘TUSZYUC001’ (U.S. Plant Pat. No. 29,025) and isdistinguished from the commercial comparison in Table 1.

TABLE 1 Comparison with Similar Variety Trait ‘Silver Anniversary’‘TUSZYUC001’ Plant height and 120 cm and 70.0 cm 35 cm and 35 cm width(maturity)

I claim:
 1. A new and distinct variety of Yucca plant named ‘SilverAnniversary’ as illustrated and described herein.